1. Field of the Invention
The invention relates to a folding device with a folding drum for producing the second longitudinal fold in products which have been produced with a rotary press.
2. Description of the Related Art
The basic construction of a folding device which comprises a folding drum is disclosed in U.S. Pat. No. 2,919,914. The folding device of this reference includes a folding blade which is secured in the folding drum and is moved into the region between two folding rolls and out again on a cycloid path. During the process, the folding blade presses the product to be folded into a gap between two folding rolls. The folding blade is fastened to a folding-blade carrier arranged on a folding-blade shaft. Both ends of the folding-blade shaft are mounted in the folding drum so that the folding blade is mounted at two points.
High flexural loading of the folding-blade shaft results from a high rotational velocity of the folding drum such that the folding-blade shaft discernibly deflects in the central region and the folding quality thus becoming worse as the velocity increases.